Many research institutions are currently studying and developing silicon carbide (SiC) devices. The SiC devices are characterized by low on-resistance, high-speed switching, high-temperature operation, and the like.
The methods of connecting the SiC devices and low thermal resistance packages for the SiC devices are already disclosed (see Patent Literatures 1 and 2, for example). Patent Literatures 1 and 2 disclose methods of fabricating a package accommodating an SiC device. The SiC device is connected to another component or a conductive surface using a TLP bonding technique.
Each TLP technique disclosed in Patent Literatures 1 and 2 is a technique to connect the SiC device by using mixed crystals of three or four types of conductive metals simultaneously formed to form a high-temperature melting point connection. Because of use of the TLP connection of three or four types of metallic materials, the constituent materials of the mixed crystals of conductive metals are complicated.
On the other hand, a composite solder article containing Sn and/or Pb and having a comparatively low melting point of not more than 430° C., for example, is already disclosed (see Patent Literature 3, for example). In Patent Literature 3, the composite solder article is characterized in that the difference in temperature between liquid and solid phases of the solder alloy is smaller than that of the basic solder material.
Moreover, metallic transfer MEMS packages using a wafer-level solder transfer technique are already disclosed (see Non-Patent Literature 1, for example). In Non-patent Literature 1, a device wafer and a package cap are bonded by the TLP technique using a relatively thin Ni—Sn layer.
Furthermore, a spray technique is known as a technique to form copper (Cu) coating having a larger area than that of bonding wire, (see Non-patent Literature 2, for example).